I am running a MK1 MR2 turbo which has a ST185 Engine and a ST205 Chargecooler. The problem seems to be cooling. It is fine around A/B roads, but on the motorway after 10 mins at constant speed, The coolant boils. I have no heater when this happens. I have tried bleeding the system and topping up, which gives me the heater back and the car will run fine for a while.
Any thoughts?
Hi wadey!
Welcome to TB!
Assuming you can account for the coolant (it's just being pushed out right?). Aside from what you don't want to hear, that being the head gasket, it might be worth checking your thermostat is opening fully.
If it isn't then light driving would be fine but higher rpm = more heat that can't escape the engine.
Just a thought.
Also I'm assuming you've ruled out any air locks at the front end?
Hth.
Chris.
take it for a planned 5 minute run on dual carriageway take it off before it boils, get the car up in the air quick and look for leaks.. it could be p1ssing out from underneath, ive seen that from cold to hot = no leak at cold/ pissing out everywhere when hot. it could be that at temperature a pipe with a bad or corroded fitting is expanding and leaking, could be the heater matrix pipe leaking right up under the frunk bulk head if your heat is gone
......in the bluecorner , fighting out of japan....
I will check for leaks under the car. It broke down twice today, both times after Motorway trips. I had the thermastat checked last week and all is Ok. Could this be caused by a faulty Blitz cap?
Looks like a failed radiator fan switch.
Hi Guys, I'm still having problems with overheating. I've had a new head gasket, radiator, rad cap and thermostat. It's fine for a couple of weeks, then the temp gauge creeps up and bubbles the expansion tank like a kettle. This also levels me with no heater and cold radiator?? Struggling to get to the bottom of this one. Any ideas??
I had a similar problem O ring on rad bleed valve was leaking slightly letting air in and air locking the system leading to a cold rad and heater.
Only happened every few weeks, must be air in your system
Waterpump failure possibly. My old Mk1.5 had similar(ish) issues.. was fine most of the time but cruising at low RPM sometimes it would overheat.. give it some revs and the temp gauge dropped back down.
Had a similar issue with our Smart Roadster, only boiled up after a motorway run followed by a spot of traffic. Turned out to be a water pipe near the turbo, was leaking just slow enough for the water to evaporate and leave no drips, under load it must have been coming out a bit quicker leading to the overheating.
New pipe = cured.
I strongly suspect a similar leak in a tucked-away place if you have already changed the above parts (hose from hell?).
Or a cracked block, which I had on my old turbo. :icon_eek:
Does anyone know a good specialist around the Midlands who could help. This isn't getting any better.
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